The present invention relates to an electrical connector socket having an ejector mechanism for removing a daughtercard or module from the socket. More particularly, the present invention relates to an improved electrical connector which provides a retention force when the daughtercard is inserted into the socket and also permits the daughtercard to be easily ejected from the socket when desired.
It is well known to provide electrical connector sockets, such as Single In-line Memory Module (SIMM) sockets, for interconnecting a first printed circuit board or mother board to a second printed circuit board or daughtercard. Typically, the sockets are formed to include an elongated slot and a plurality of electrical terminals coupled to the housing adjacent to the slot. When the daughtercard is inserted into the slot of the socket, conductive surfaces on the daughtercard engage the terminals to couple the daughtercard to the socket electrically. The terminals are also coupled to conductive traces on the mother board so that when the daughtercard is inserted into the socket, the daughtercard is electrically coupled to the mother board. For examples of SIMM socket configurations see, for example, U.S. Pat. No. 5,013,264 to Tondreault and U.S. patent application Ser. No. 07/759,409, owned by the assignee of the present invention, and incorporated herein by reference.
One problem associated with conventional electrical connectors is that it is often difficult to extract a daughtercard that is held in a socket formed in an electrical connector. It is understood that a plurality of sockets may be located adjacent each other with daughtercards in each of the sockets. In such tight quarters it is often difficult for a technician to remove a selected daughtercard from the connector socket manually by hand or using a tool. Unless precautions are taken, the daughtercard can be damaged during extraction of the daughtercard from the socket. Therefore, it is desirable to provide an ejector mechanism coupled to the socket to facilitate ejection of the daughter card from the socket.
It is known to provide ejectors coupled to the sockets to assist with the removal of daughtercards from the socket. One such ejector is disclosed in U.S. Pat. No. 5,147,211 to Tondreault et al. The '221 patent discloses an ejector for selectively ejecting one of first and second daughtercards located in adjacent elongated slots of a socket. The device disclosed in the '211 patent therefore provides means for selectively ejecting first and second daughtercards in a dual-row socket.
The present invention provides an improved design for an ejector for a single row socket. It is known to provide ejectors for such single row sockets. See, for example, U.S. Pat. No. 4,990,097 to Billman, et al. The '097 patent discloses a connector having extraction members which can be lifted upwardly relative to the socket to permit a circuit board to be withdrawn from the socket. However, it is often difficult to access the extraction members. A great deal of room is required beyond the edge of the extraction members to permit a technician to grip under a ledge of the extraction members and lift. In addition, a relatively large amount of force must be applied to the extraction members to remove the circuit board from the socket.
Another single row socket ejector apparatus is disclosed in U.S. Pat. No. 5,074,800 to Sasao et al. The Sasao '800 patent discloses first and second ejection levers pivotably coupled to opposite ends of a connector housing. In order to insert a printed circuit board into a slot of housing, both ejection levers are pivoted outwardly into to an ejection position. As the board is inserted downwardly into the slot of the housing and engages the ejection levers, the ejection levers rotate toward a locking position. A user must hold and guide the circuit board carefully until the board is above the slot in an aligned position so that the contacts on the board mate with the contact terminals in the housing. Having ejection levers on both ends of housing provides a substantial amount of end play and make it difficult to align board in the correct position relative to housing.
A problem associated with conventional sockets is that the daughtercard tends to dislodge from the socket during handling or during motor or fan vibration. Such dislodging can cause intermittent or failed signal paths between the daughtercard and the mother board.
An object of the present invention is to facilitate ejection of a daughtercard from a socket, while improving the retention force on the daughtercard to retain the daughtercard in the socket and while facilitating alignment of the daughtercard with the socket during insertion of the daughtercard into the socket.
According to one aspect of the present invention, an electrical connector is provided for receiving a daughtercard having a plurality of conductive surfaces formed thereon. The connector includes a socket having a first end and a second end. The socket is formed to include an elongated slot extending between the first and second ends for receiving the daughtercard therein and a plurality of electrical terminals for engaging the plurality of conductive surfaces formed the daughtercard for electrically coupling the daughtercard to the socket. The connector also includes a post coupled to the second end of the socket in a fixed position relative to the socket to guide insertion of the daughtercard into the socket so that the plurality of conductive surfaces formed the daughtercard are aligned with the plurality of electrical terminals of the socket. The post is formed to include means for engaging opposite sides of the daughtercard adjacent the post to retain the daughtercard within the socket. The connector further includes an ejector coupled to the first end of the socket. The ejector includes means for retaining the daughtercard in the socket upon insertion of the daughtercard into the socket and means for ejecting an end of the daughtercard adjacent the ejector out of the elongated slot upon movement of the ejector relative to the socket while leaving an opposite end of the daughtercard adjacent the post in the elongated slot of the socket.
In the illustrated embodiment, the retaining means of the ejector includes first and second spring arms for engaging opposite sides of the daughtercard upon insertion of the daughtercard into the socket. The first and second spring arms of the ejector each include a head portion configured to enter an aperture formed in the daughtercard adjacent the ejector from opposite sides of the daughtercard. The head portions of the ejector arms include a ramp shaped edge surface configured to engage the daughtercard and apply a retention force normal to the daughtercard. The head portions of the ejector arms also include a bottom surface for applying a retention force against the daughtercard downwardly into said elongated slot of the socket. The head portions of the ejector arms further include side ramped surfaces to force the first and second arms of the ejector apart automatically during insertion of the daughtercard into socket or during ejection of the daughtercard from the socket.
Also in the illustrated embodiment, the ejecting means includes means for engaging the daughtercard to force an end of the daughtercard adjacent the first end of the socket out of the elongated slot upon movement of the ejector relative to the socket. The ejector is pivotably coupled to the first end of the socket and movable from an upright retention position in which the retaining means engages opposite sides of the daughtercard to retain the daughtercard in the socket to an outwardly pivoted ejection position so that the ejecting means forces said end of the daughtercard adjacent the ejector out of the elongated slot. Advantageously, the spring arms of the ejector are formed to include means for permitting the daughtercard to be inserted into the socket with the ejector in either its upright retention position or its outwardly pivoted ejection position.
The engaging means of the post includes a pair of spring arms projecting away from the post for engaging opposite sides of the daughtercard adjacent the second end of the socket to retain the daughtercard within the socket. The arms of the post each include a head portion configured to enter an aperture formed in the daughtercard for engaging opposite sides of the daughtercard to retain and stabilize the daughtercard in the socket. The head portions of the post arms have a configuration identical to the head portions of the ejector. Therefore, the head portions of the post arms include a ramp shaped edge surface configured to engage the daughtercard and apply a force normal to the daughtercard and a bottom surface for applying a force against the daughtercard downwardly into said elongated slot of the socket. The head portions of the post arms also include side ramped surfaces to force the post arms apart automatically during insertion of the daughtercard into the socket or during ejection of the daughtercard from the socket.
Insertion of the daughtercard into the socket of the present invention is simple. The daughtercard is first aligned with the socket using the fixed post as a guide. This is an advantage over the prior art device illustrated in the '800 patent discussed above in which the card may become misaligned due to the end play caused by having ejection levers at both ends of the socket. As the daughtercard is inserted into the socket of the present invention, the bottom surface of the daughtercard engages the bottom surface of the ejector and causes rotation of ejector about its pivot axis. The ramped surfaces on the heads of the ejector cause the arms of the ejector to move apart automatically as they contact a side edge of the daughtercard. There is no need to exert an external force on the ejector to cause the ejector to pivot to the retention position in which the ramped heads of the ejector enter the aperture from opposite sides of the daughtercard to stabilize and retain the daughtercard in the socket. In fact, the daughtercard can be inserted with the ejector in its upright retention position. The heads of the arms formed coupled to the fixed post enter the aperture at the opposite end of the daughtercard. Flat bottom surfaces on heads of the arms of the ejector and the post prevent movement of daughtercard upwardly out of the socket.
When it is desired to remove the daughtercard from the socket, the ejector is rotated about its pivot axis. This movement forces the end of the daughtercard adjacent the ejector to rotate out of the socket. The ramped surfaces of the heads of the ejector engage a side wall defining the aperture in the daughtercard to force the arms of the ejector outwardly to disengage the heads of the ejector from the aperture. After the ejector pushes the end of the daughtercard adjacent the ejector out of the socket, an operator can grab the raised corner of the daughtercard and "peel" the daughtercard the rest of the way out the socket by continuing to rotate daughtercard using the fixed post to provide leverage.
According to another aspect of the present invention, an ejector is provided for ejecting a daughtercard from an elongated slot formed in an electrical connector socket housing. The ejector includes a body having means for ejecting an end of the daughtercard adjacent the ejector out of the elongated slot upon movement of the ejector relative to the socket housing. The body is also formed to include first and second crimp surfaces for engaging an end edge of the daughtercard to stabilize the daughtercard in the socket.
In the illustrated embodiment, means is also provided for biasing the ejector body in a direction toward the daughtercard to hold the first and second crimp surfaces against the daughtercard. The biasing means includes first and second wedges formed on opposite side surfaces of the ejector body, and first and second locking tabs formed on the socket housing for engaging the first and second wedges, respectively, to apply a biasing force to the ejector body in a direction toward the daughtercard. The first and second crimp surfaces are illustratively convergent to accommodate daughtercards having various lengths and thicknesses.
The first and second locking tabs also engage the opposite side surfaces of the ejector body to apply opposing, inwardly directed forces to the ejector body, thereby centralizing and stabilizing the ejector body within the socket housing. Also in the illustrated embodiment, the ejector further includes first and second raised surfaces formed on the opposite side surfaces of the body of the ejector and configured so that the first and second locking tabs engage the first and second raised surfaces respectively.
The ejector also includes first and second lead in ramp surfaces formed on the ejector body above the first and second crimp surfaces, respectively. These first and second lead in ramp surfaces reduce the likelihood of stubbing a bottom surface of the daughtercard against the ejector body during insertion of the daughtercard into the socket housing.
Additional objects, features, and advantages of the invention will become apparent to those skilled in the art upon consideration of the following detailed description of a preferred embodiment exemplifying the best mode of carrying out the invention as presently perceived.